Switch operators are used to provide actuation of switches located in the housing of primary entrance units or electrical switch gear cabinets. The actuators of switch operators are commonly located on the outside of the housing of electrical switch gear cabinets. The switches themselves are mounted somewhere inside the cabinet. The actuators typically include a handle to facilitate their movement. Because of the relative locations of the switch actuators and the switches they control, some mechanism must be provided for coupling the movement of each actuator to its respective switch. Previously, switch operators have employed chain drive mechanisms to transfer the motion of an actuator to its respective switch. Other switch operators have employed shafts with universal joints to provide the coupling of an actuator to its respective switch. The assembly of such coupling devices is complicated and time consuming. For example, to assemble a coupling device comprised of a chain drive mechanism, the chain generally must be cut to length, connected and then aligned. Consequently, there is a need for a switch operator that is simple, inexpensive and easy to install.
Interlock mechanisms are used to limit the operation of switch operators to meet safety locking requirements. Previously, interlock mechanisms have employed a Kirk lock to meet the safety locking requirements. A Kirk lock is a locking mechanism that prevents switch actuation unless a corresponding key is inserted in the Kirk lock. After the key is inserted, a user may actuate a switch. Ideally, the key should be kept at a separate and controlled location from the switch operator. The Kirk lock provides only a minimum level of safety protection for the user of the switch operator. In addition, if the key is lost or misplaced, a user may not be able to actuate a switch when required. Accordingly there is need for an interlock mechanism that provides the safety locking requirements without the use of a Kirk lock.
The present invention satisfies these needs.